What does aggregation mean?
The definition of aggregation
Ag`gre*ga”tion, n. [Cf. LL. aggregatio, F. agrégation.]
The act of aggregating, or the state of being aggregated; collection into a mass or sum; a collection of particulars; an aggregate.
Each genus is made up by aggregation of species. Carpenter.
A nation is not an idea only of local extent and individual momentary aggregation, but . . . of continuity, which extends in time as well as in numbers, and in space. Burke.